Bronchoarterial Ratio Research Articles

Determinant of Bronchoarterial Ratio in a Patient Undergoing Computed Tomography Chest

Background: Respiratory diseases pose a significant challenge in Nepali clinical settings due to elevated smoking rates and environmental risks. This study explores the structural changes in conditions such as asthma, chronic obstructive pulmonary disease, and bronchiectasis, utilizing noninvasive multi-detector computed tomography to assess airway remodeling. Despite conflicting western literature on bronchoarterial ratios, this research emphasizes the importance of evaluating these ratios in the Nepalese context for predicting airway disease severity. Materials and Methods: The cross-sectional study conducted at Nobel Medical College and Teaching Hospital involved 129 participants aged over 20 undergoing chest computed tomography. It aimed to measure the bronchoarterial ratio and investigate its associations with age, gender, smoking history, and altitude of residence. Bronchoarterial ratios was calculated using averaged short-axis diameters of the right apical and right posterior basal segmental bronchi, excluding the left lung due to motion artifacts. Results: Analysis indicated a Mean Bronchoarterial Ratio of 0.823 (SD 0.151), with the apical and basal segment BARs at 0.832 (SD 0.148) and 0.814 (SD 0.153), respectively. Notably, individuals aged over 65 who were smokers exhibited a significant increase in BAR. Additionally, a higher altitude of residence demonstrated a significant correlation with the Bronchoarterial ratio in the apical lung segment. Conclusion: This study provides valuable insights into the bronchoarterial ratio within the Nepalese population, considering age, gender, smoking history, and altitude of residence. The findings underscore the potential relevance of these ratios in conditions involving airway remodeling, contributing to the understanding of respiratory diseases in this specific demographic.

Aspergillus-sensitized asthma in children.

Asthma is the most common chronic respiratory disease in childhood. Aspergillus fumigatus sensitivity may be involved in the pathogenesis of asthma by leading to different clinical presentations. To investigate the demographic, clinical, laboratory, and radiological characteristics of A. fumigatus sensitivity in childhood asthma and identify associated risk factors and diagnostic parameters. A total of 259 children with asthma were included in the study, 7 (2.7%) with allergic bronchopulmonary aspergillosis (ABPA), 84 (32.4%) with A. fumigatus-sensitized asthma (Af-SA), and 168 (64.9%) with A. fumigatus-unsensitized asthma (Af-UA). Aspergillus sensitivity was associated with early asthma onset and longer asthma duration. Total IgE level and asthma severity are highest in ABPA and higher in Af-SA. Absolute eosinophil count was higher, and FEV1 was lower in Af-SA and ABPA. Aspergillus fumigatus was associated with greater odds of being male (odds ratio [OR], 2.45), having atopic dermatitis (OR, 3.159), Alternaria sensitivity (OR, 10.37), and longer asthma duration (OR, 1.266). The best cut-off values for detecting A. fumigatus positivity were 363.5 IU/mL for total IgE and 455 cells/μL for absolute eosinophil count. In Af-SA compared to Af-UA, centrilobular nodules and peribronchial thickening were more common, and the bronchoarterial ratio was higher. Aspergillus sensitivity is a strong allergic stimulus in asthma, leading to laboratory, structural, clinical, and functional consequences. Af-SA is a distinct asthma endotype independent of ABPA that is characterized by increased risk of severe clinical presentations and impaired lung function.

Radiographic Outcomes in Pediatric Bronchiectasis and Factors Associated with Reversibility.

Rationale: Conventionally considered irreversible, bronchiectasis has been demonstrated to be reversible in children in small studies. However, the factors associated with radiographic reversibility of bronchiectasis have yet to be defined. Objectives: In a large cohort of children with bronchiectasis, we aimed to determine: 1) if and to what extent bronchiectasis is reversible and 2) factors associated with radiographic chest high-resolution computed tomography (cHRCT) resolution. Methods: We identified children with bronchiectasis who had a repeat multidetector cHRCT scan between 2010 and 2021. We excluded those with cystic fibrosis, surgical pulmonary resection, traction bronchiectasis only, or lobar opacification. Measurements and Main Results: cHRCT scans were scored using the modified Reiff score (MRS) with a pediatric correction. Resolution was defined as an absence of abnormal bronchoarterial ratio (>0.8) on the second cHRCT scan. We included 142 children (median age, 5 years; IQR, 2.6-7.4). Inter- and intrarater agreement in MRSs was excellent (weighted κ = 0.83-0.86 and 0.95, respectively). There was radiographic resolution in 57 of 142 patients (40.1%), improvement in 56 of 142 (39.4%), and no change or worsening in 29 of 142 (20.4%). Pseudomonas aeruginosa (PsA) was absolutely associated with a lack of resolution. On multivariable regression, in those without PsA cultured, younger age at the time of diagnosis (risk ratio [RR], 0.94; 95% confidence interval [CI], 0.88-0.99), lower MRS (RR, 0.89; 95% CI, 0.82-0.97), and lower annual rate of exacerbations requiring intravenous antibiotic therapy (RR, 0.60; 95% CI, 0.37-0.98) increased the likelihood of radiographic resolution. Conclusions: This first large cohort confirms that bronchiectasis in children is often reversible with appropriate management. Younger children and those with lesser radiographic severity at diagnosis were most likely to exhibit radiographic reversibility, whereas those with PsA infection were least likely.

Methods to Measure the Broncho-Arterial Ratio and Wall Thickness in the Right Lower Lobe for Defining Radiographic Reversibility of Bronchiectasis

Methods to Measure the Broncho-Arterial Ratio and Wall Thickness in the Right Lower Lobe for Defining Radiographic Reversibility of Bronchiectasis

Pixel-level image analysis to derive the broncho-artery (BA) ratio employing HRCT scans: A computer-aided approach

Bronchiectasis in children is a major health issue which can be life-threatening if not diagnosed and effectively treated. In the diagnosis of bronchiectasis, an increased broncho-arterial (BA) ratio is considered a significant marker. The BA ratio is measured by evaluating BA pairs, using high-resolution computed tomography (HRCT) scans. Detecting BA pairs automatically is challenging due to the complex characteristics of BA pairs and the ambiguous appearance of the bronchi. This study proposes an effective computerized approach to detect BA pairs and assess BA ratio using HRCT scans of children and employing computer-aided techniques and novel custom-build algorithms. Attention is given to reconstructing broken bronchial walls and identifying discrete BA pairs using custom-built kernel based and patch-based algorithms for pixel-level image analysis. To detect BA pairs, the lung region is segmented in the HRCT slices and image preprocessing techniques, including noise reduction, binarizing, largest contour detection and a hole-filling algorithm, are applied. A histogram analysis method is introduced to clean the images. A kernel-based algorithm is proposed to reconstruct the pixel distribution if the bronchial wall is so that the bronchi can be detected precisely. Potential arteries are detected using balanced histogram thresholding, morphological opening and an approach based on four conditions related to the object area circularity, rectangular boundary box ratio and enclosing circle area ratio. Potential bronchi are detected through matching of object coordinates with potential arteries, hole-filling and four condition based approaches. The potential BA pairs are detected by matching the coordinates of potential bronchi with those of potential arteries as the artery and bronchus are adjacent to each other in BA pairs. Finally, from the potential BA pairs, actual BA pairs are identified using a custom-built patch algorithm. The study is conducted using 2471 HRCT slices of seven children, obtained from the Royal Darwin Hospital, Australia. The BA ratio is derived based on the ratio of diameters, major axis lengths, minor axis lengths, area, convex hull and equivalent diameter where the BA ratios are respectively 0.51–0.65, 0.49–0.59, 0.59–0.77, 0.25–0.42, 0.29–0.47, 1.5–2 and 0.50–0.65.

An Automated Broncho-Arterial (BA) Pair Segmentation Process and Assessment of BA Ratios in Children with Bronchiectasis Using Lung HRCT Scans: A Pilot Study.

Bronchiectasis in children can progress to a severe lung condition if not diagnosed and treated early. The radiological diagnostic criteria for the diagnosis of bronchiectasis is an increased broncho-arterial (BA) ratio. From high-resolution computed tomography (HRCT) scans, the BA pairs must be detected first to derive the BA ratio. This study aims to identify potential BA pairs from HRCT scans of children undertaken to evaluate suppurative lung disease through an automated approach. After segmenting the lung regions, the HRCT scans are cleaned using a histogram analysis-based approach followed by a potential arteries identification process comprising four conditions based on imaging features. Potential arteries and their connected components are extracted, and potential bronchi are identified. Finally, the coordinates of potential arteries and potential bronchi are matched as the last step of BA pairs extraction. A total of 8-50 BA pairs are detected for each patient. Additionally, the area and several diameters of the bronchi and arteries are measured, and BA ratios based on these are calculated. Through this approach, the BA pairs of a CT scan datasets are detected and utilizing a deep learning model, a high classification test accuracy of 98.53% is achieved, validating the robustness of the proposed BA detection approach. The results show that visible BA pairs can be identified and segmented automatically, and the BA ratio calculated may help diagnose bronchiectasis with less effort and time.

Non cystic fibrosis-related bronchiectasis in children: etiological structure, clinical and laboratory and computed tomographic characteristics

Aim. To establish the etiological structure and to present clinical and laboratory and instrumental characteristics of bronchiectasis (BE) not associated with cystic fibrosis (CF) in children.
 Materials and methods. Sixty-seven hospitalised patients with BЕ not related to CF were followed up between 2017 and 2022. Examination methods: clinical-anamnestic method, general clinical laboratory investigations, investigation of allergological and immune status, phagocytosis system, determination of concentration of specific IgE and IgG to fungi of genus Aspergillus, sweat test, radiological examination and computed tomography (CT) of chest organs, bronchoscopy, Bacteriological examination of sputum and/or tracheobronchial aspirates, nasal and/or bronchial ciliary motility, esophagogastroduodenoscopy, 24-hour pH-metry, intra-esophageal combined impedance-pH-metry, genetic study, lung biopsy.
 Results. Etiologic factors of BЕ not associated with CF in children were severe pneumonia (22%), primary ciliary dyskinesia (22%), bronchial asthma (13%), Williams-Campbell syndrome (7%), bronchial foreign bodies (7%), gastroesophageal reflux disease (6%), Bronchopulmonary dysplasia (6%), postinfectious bronchiolitis obliterans (5%), allergic bronchopulmonary aspergillosis (3%), chronic granulomatous disease (3%), AIDS (1%), prolonged bacterial bronchitis (1%), brain-lung-thyroid syndrome (1%). The clinical picture is characterized by cough (91%), shortness of breath (67%), fever during exacerbation (48%), chest pain (24%), exercise intolerance (55%), drumstick symptom (9%), moist (76%) and dry wheezing (37%). CT-semiotics of BЕ not associated with CF is characterized by localization in one (58%) or several (42%) lobes; traction (42%), non-traction (49%) B and their combination (9%); increased broncho-arterial ratio 0.9; thickening of bronchial wall; "mosaic perfusion"/"air-trap" symptom (9%); more frequent involvement of lower lungs (64%). The main infectious agents in BЕ not associated with CF were Haemophilus influenzae, Pseudomonas aeruginosa, Staphylococcus aureus.
 Conclusion. On the basis of a multicentre study, the etiological structure, clinical and laboratory and CT-characteristics of non-CF ВE in children were established.

Radiology Imaging of Bronchiectasis in Children and Adolescents (Literature Review with Own Observations)

Timely detection of bronchiectasis in children is of great prognostic value. The importance of modern bronchiectasis in children is due to their possible reversibility over time with effective treatment, as well as a number of significant differences between bronchiectasis in childhood and onset in children, which may reflect different phenotypes of bronchiectasis. In adult patients with bronchiectasis that began in childhood, the pathological process has a more severe and worse prognosis compared to bronchiectasis that began in adulthood. In 2020, the European Respiratory Society proposed a new formulation of the terminal «bronchiectasis» for children and adolescents, now this term refers to an abnormal expansion of the bronchi by computed tomography (CT) of the chest, which, if detected early, can be reversible. CT is the true «gold standard» for confirming bronchiectasis in children and adolescents. This method is included in the minimum set of tests for children and adolescents with suspected bronchiectasis according to the recommendations of the European Respiratory Society. When conducting CT, it is recommended to perform a continuous spiral scan with a collimation of 1 mm, the study is carried out without intravenous use using low-dose protocols. To assess the state of the bronchi in children and adolescents, it is necessary to use the pediatric norms of the broncho-arterial ratio (> 0.8). At the same time, radiation methods are not decisive in establishing the causes of bronchiectasis and only in rare cases can help in establishing bronchiectasis. Dynamic observation of bronchiectasis for children and adolescents is determined individually. Consideration should be given to repeat chest computed tomography scans to answer the question that will change treatment.

Refining diagnostic criteria for paediatric bronchiectasis using low-dose CT scan

BackgroundThere is a current lack of consensus amongst paediatric radiologists and respiratory paediatricians as to the correct CT definition of bronchiectasis in children. Using contemporary low-dose CT, our objectives were to determine the upper limit of normal for broncho-arterial ratio (BAR) in children and to evaluate the effect of age and general anaesthesia. MethodsMeasurements of 330 broncho-arterial ratios from 51 children (0–19 years) undergoing low-dose CT chest for non-respiratory indications were performed by 3 blinded observers (two radiologists, one respiratory physician) using four different methods. Inter-observer reliability, mean BAR and reference ranges (mean±2SD) were calculated. Correlation between age and BARs were examined. Mean BAR for CT under general anaesthesia and CT awake were compared. ResultsInter-observer correlation was extremely high for all measurements (0.93–0.97). There was a weak positive correlation between age and BAR in the CT-awake group (r = 0.33, 95%CI: 0.03–0.57; p = 0.031) using the inner-bronchial wall to artery, short-axis measurement. CT under general anaesthesia showed significantly higher BAR compared to CT-awake [mean difference 0.13 (95%CI: 0.05–0.22; p = 0.004)]. For the CT-awake group, the mean BAR was 0.65 (range: 0.42 to 0.89), with no child having a BAR above 0.9. ConclusionUsing a standardised approach, we have shown that a broncho-arterial ratio above 0.9 in children undergoing awake CT is abnormal and suggests airway widening or radiological bronchiectasis. Children undergoing CT under anaesthesia have higher BARs than those undergoing awake CT. A weak positive correlation between broncho-arterial ratio and age was observed, hence, age-adjusted cut-offs for BAR warrant further study.

Diagnostic imaging in adult non-cystic fibrosis bronchiectasis.

Radiology plays a key role in the diagnosis of bronchiectasis, defined as permanent dilatation of the bronchial lumen. Volumetric thin-section multidetector computed tomography is an excellent noninvasive modality to evaluate bronchiectasis. Bronchiectasis is categorised by morphological appearance. Cylindrical bronchiectasis has a smooth tubular configuration and is the most common form. Varicose bronchiectasis has irregular contours with alternating dilating and contracting lumen. Cystic bronchiectasis is the most severe form and exhibits saccular dilatation of bronchi. Bronchial dilatation is the hallmark of bronchiectasis and is evaluated in relation to the accompanying pulmonary artery. A broncho–arterial ratio exceeding 1:1 should be considered abnormal. Normal bronchi are narrower in diameter the further they are from the lung hila. Lack of normal bronchial tapering over 2 cm in length, distal from an airway bifurcation, is the most sensitive sign of bronchiectasis. Findings commonly associated with bronchiectasis include bronchial wall thickening, mucus plugging and tree-in-bud opacities. Bronchiectasis results from a myriad of conditions, with post-infectious bronchiectasis being the most common. Imaging can sometimes discern the cause of bronchiectasis. However, in most cases it is nonspecific or only suggestive of aetiology. While morphological types are nonspecific, the distribution of abnormality offers clues to aetiology.Key pointsBronchiectasis is a chronic progressive condition with significant disease burden and frequent exacerbations, for which the diagnosis relies on cross-sectional imaging.The major imaging findings include bronchial dilatation, bronchial contour abnormalities and visualisation of the normally invisible peripheral airways.Bronchiectasis is the end result of various conditions, including immunodeficiencies, mucociliary disorders and infections. Imaging is often nonspecific with regard to aetiology but can be suggestive.Distribution of abnormality in the lung offers helpful clues for establishing aetiology.Educational aimsTo review the cross-sectional imaging appearance of bronchiectasis and the common associated findings.To get a sense of how radiology can aid in establishing the aetiology of bronchiectasis.

Ratio of the Bronchial Lumen to Pulmonary Artery Diameter in Rhesus Macaques (Macaca mulatta) without Clinical Pulmonary Disease.

In human medicine, CT is widely used to detect changes in bronchial luminal diameter. The diameter of the artery that runs adjacent to the bronchus does not change dramatically along the airway path, such that this artery can be used as a reference to detect changes in the bronchial luminal diameter. The bronchoarterial ratio is increasingly used in veterinary medicine for the detection of lower airway diseases in animals. The purpose of this study was to establish the bronchoarterial ratio in rhesus macaques. We used CT to evaluate 12 rhesus macaques (Macaca mulatta) without clinical signs of pulmonary diseases and measured the bronchoarterial ratio in the right and left superior, middle, inferior and cardiac lung lobes. The overall bronchoarterial ratio (mean ± 1 SD) at all 7 locations in the 12 macaques was 0.59 ± 0.05. Moreover, there was no correlation between the BA ratio and age or sex in the study population. However, the BA ratio and weight of animals showed positive linear correlation. In this study, we established the reference range for the bronchoarterial ratio in clinically healthy rhesus macaques. This ratio is consistent among lung lobes and between animals.

Bronchoarterial ratio in never-smokers adults: Implications for bronchial dilation definition.

Bronchiectasis manifests as recurrent respiratory infections and reduced lung function. Airway dilation, which is measured as the ratio of the diameters of the bronchial lumen (B) and adjacent pulmonary artery (A), is a defining radiological feature of bronchiectasis. A challenge to equating the bronchoarterial (BA) ratio to disease severity is that the diameters of airway and vessel in health are not established. We sought to explore the variability of BA ratio in never-smokers without pulmonary disease and its associations with lung function. Objective measurements of the BA ratio on volumetric computed tomography (CT) scans and pulmonary function data were collected in 106 never-smokers. The BA ratio was measured in the right upper lobe apical bronchus (RB1) and the right lower lobe basal posterior bronchus. The association between the BA ratio and forced expiratory volume in 1 s (FEV1 ) was assessed using regression analysis. The BA ratio was 0.79 ± 0.16 and was smaller in more peripheral RB1 bronchi (P < 0.0001). The BA ratio was >1, a typical threshold for bronchiectasis, in 10 (8.5%) subjects. Subjects with a BA ratio >1 versus ≤1 had smaller artery diameters (P < 0.0001) but not significantly larger bronchial lumens. After adjusting for age, gender, race and height, the BA ratio was directly related to FEV1 (P = 0.0007). In never-smokers, the BA ratio varies by airway generation and is associated with lung function. A BA ratio >1 is driven by small arteries. Using artery diameter as reference to define bronchial dilation seems inappropriate.

Computed Tomographic Features of Saccular Type of Bronchiectasis in a Dog

A 9-year-old, castrated male Malamute dog was presented with chronic cough. On thoracic computed tomography, non-tapered and dilated peripheral bronchi were detected. Bronchoarterial ratio was about 2.2. The dilated bronchi appeared as a cluster of grapes especially in left cranial, left caudal and right middle lung lobe. Based on the computed tomographic findings, the diagnosis was made as the saccular type of bronchiectasis.

Computed tomographic bronchioarterial ratio for brachycephalic dogs without pulmonary disease.

The bronchoarterial (BA) ratio measured with computed tomography is widely used in human medicine to diagnose bronchial dilation or collapse. Although use of the BA ratio in veterinary medicine has been recently studied, this has not been evaluated in brachycephalic dogs predisposed to bronchial diseases including bronchial collapse. The purpose of this study was to establish BA ratios for brachycephalic dogs and compare the values with those of non-brachycephalic dogs. Twenty-three brachycephalic dogs and 15 non-brachycephalic dogs without clinical pulmonary disease were evaluated. The BA ratio of the lobar bronchi in the left and right cranial as well as the right middle, left, and right caudal lung lobes was measured. No significant difference in mean BA ratio was observed between lung lobes or the individual animals (p = 0.148). The mean BA ratio was 1.08 ± 0.10 (99% CI = 0.98~1.18) for brachycephalic dogs and 1.51 ± 0.05 (99% CI = 1.46~1.56) for the non-brachycephalic group. There was a significant difference between the mean BA ratios of the brachycephalic and non-brachycephalic groups (p = 0.00). Defining the normal limit of the BA ratio for brachycephalic breeds may be helpful for diagnosing bronchial disease in brachycephalic dogs.

EFFECT OF VENTILATION TECHNIQUE AND AIRWAY DIAMETER ON BRONCHIAL LUMEN TO PULMONARY ARTERY DIAMETER RATIOS IN CLINICALLY NORMAL BEAGLE DOGS

In dogs, a mean broncho-arterial ratio of 1.45 ± 0.21 has been previously defined as normal. These values were obtained in dogs under general inhalational anesthesia using a single breath-hold technique. The purpose of the study was to determine whether ventilation technique and bronchial diameter have an effect on broncho-arterial ratios. Four healthy Beagle dogs were scanned twice, each time with positive-pressure inspiration and end expiration. For each ventilation technique, broncho-arterial ratios were grouped into those obtained from small or large bronchi using the median diameter of the bronchi as the cutoff value. Mean broncho-arterial ratios obtained using positive-pressure inspiration (1.24 ± 0.23) were statistically greater than those obtained at end expiration (1.11 ± 0.20) P = 0.005. There was a strong positive correlation between bronchial diameter and broncho-arterial ratios for both ventilation techniques (positive-pressure inspiration rs = .786, P < 0.0005 and end expiration rs = .709, P < 0.0005). Mean broncho-arterial ratio for the large bronchi obtained applying positive-pressure inspiration was 1.39 cm ± 0.20 and during end expiration was 1.22 cm ± 0.20. Mean broncho-arterial ratio for the small bronchi obtained during positive-pressure inspiration was 1.08 cm ± 0.13 and during end expiration was 1.01 cm ± 0.13. There was a statistically significant difference between these groups (F = 248.60, P = 0.005). Findings indicated that reference values obtained using positive-pressure inspiration or from the larger bronchi may not be applicable to dogs scanned during end expiration or to the smaller bronchi.

QUANTITATIVE AND QUALITATIVE COMPUTED TOMOGRAPHIC CHARACTERISTICS OF BRONCHIECTASIS IN 12 DOGS

Bronchiectasis is an irreversible dilatation of the bronchi resulting from chronic airway inflammation. In people, computed tomography (CT) has been described as the noninvasive gold standard for diagnosing bronchiectasis. In dogs, normal CT bronchoarterial ratios have been described as <2.0. The purpose of this retrospective study was to describe quantitative and qualitative CT characteristics of bronchiectasis in a cohort of dogs with confirmed disease. Inclusion criteria for the study were thoracic radiography, thoracic CT, and a diagnosis of bronchiectasis based on bronchoscopy and/or histopathology. For each included dog, a single observer measured CT bronchoarterial ratios at 6 lobar locations. Qualitative thoracic radiography and CT characteristics were recorded by consensus opinion of two board-certified veterinary radiologists. Twelve dogs met inclusion criteria. The mean bronchoarterial ratio from 28 bronchiectatic lung lobes was 2.71 ± 0.80 (range 1.4 to 4.33), and 23/28 measurements were >2.0. Averaged bronchoarterial ratios from bronchiectatic lung lobes were significantly larger (P < 0.01) than averaged ratios from nonbronchiectatic lung lobes. Qualitative CT characteristics of bronchiectasis included lack of peripheral airway tapering (12/12), lobar consolidation (11/12), bronchial wall thickening (7/12), and bronchial lumen occlusion (4/12). Radiographs detected lack of airway tapering in 7/12 dogs. In conclusion, the most common CT characteristics of bronchiectasis were dilatation, a lack of peripheral airway tapering, and lobar consolidation. Lack of peripheral airway tapering was not visible in thoracic radiographs for some dogs. For some affected dogs, bronchoarterial ratios were less than published normal values.

S108 Expert consensus on diagnostic criteria and tertiary service requirements for bronchiectasis

IntroductionThere are no agreed diagnostic criteria for bronchiectasis and no stated minimum requirements for a tertiary service. The Northern Bronchiectasis Group aimed to use the validated RAND technique to form...

HIGH‐RESOLUTION COMPUTED TOMOGRAPHY BRONCHIAL LUMEN TO PULMONARY ARTERY DIAMETER RATIO IN ANESTHETIZED VENTILATED CATS WITH NORMAL LUNGS

High-resolution computed tomography (CT) is the preferred noninvasive tool for diagnosing bronchiectasis in people. A criterion for evaluating dilation of the bronchus is the bronchial lumen to pulmonary artery diameter (bronchoarterial ratio [BA ratio]). A ratio of > 1.0 in humans or > 2.0 in dogs has been suggested as a threshold for identifying bronchiectasis. The purpose of this study was to establish the BA ratio in normal cats. Fourteen specific pathogen-free cats were selected for analysis of thoracic CT images. The BA ratios of the lobar bronchi of the left cranial (cranial and caudal parts), right cranial, right middle, left caudal, and right caudal lung lobes were measured. The mean of the mean BA ratio of all lung lobes was 0.71 +/- 0.05. Individual BA ratios ranged from 0.5 to 1.11. Comparing individual lobes for each cat, there was no significant difference (P = 0.145) in mean BA ratio between lung lobes. A mean BA ratio for these normal cats was 0.71 +/- 0.1, which suggests an upper cut-off normal value > 0.91 (mean +/- 2 standard deviations) between normal and abnormal cats.

Bronchoarterial Ratio on High-Resolution CT Scan of the Chest in Children Without Pulmonary Pathology: Need to Redefine Bronchial Dilatation

The radiologic definition of airway dilatation and bronchiectasis in children has substantial limitations. Bronchoarterial (BA) ratio is a commonly used criterion to define airway dilatation despite the lack of normative pediatric data. The objective of our study was to determine the range of normal bronchial to accompanying arterial diameter ratio on high-resolution CT scan of the chest in children and compare it with the available adult data. Children undergoing multidetector CT scan of the chest for nonpulmonary conditions at a single center were prospectively identified. High-resolution reconstruction was performed on those included and both airway lumen and vessel diameters were measured in the upper and lower lobes of both lungs. Mean BA ratio was calculated for each included child, and its correlation with age was assessed. Forty-one children were included; the mean (SD) BA ratio was 0.626 (0.068) (range, 0.437-0.739). This ratio was lower than comparable adult data (combined mean [SD], 0.676 [0.12]; P = .01). No correlation was found with age in our cohort (r = -0.21, P = .19). There was no difference in the ratio based on laterality or lobe. In the pediatric age group, the airway is significantly smaller than the adjoining vessel. Using the radiologic criteria of BA ratio > 1 to define bronchial dilatation would underestimate the presence and extent of bronchiectasis, leading to delayed and missed diagnosis. This highlights the need to redefine the criteria for bronchial dilatation in children.

Diagnosing and preventing chronic suppurative lung disease (CSLD) and bronchiectasis

SummaryCurrent diagnostic labelling of childhood bronchiectasis by radiology has substantial limitations. These include the requirement for two high resolution computerised tomography [HRCT] scans (with associated adversity of radiation) if criteria is adhered to, adoption of radiological criteria for children from adult data, relatively high occurrence of false negative, and to a smaller extent false positive, in conventional HRCT scans when compared to multi-detector CT scans, determination of irreversible airway dilatation, and absence of normative data on broncho-arterial ratio in children.A paradigm presenting a spectrum related to airway bacteria, with associated degradation and inflammation products causing airway damage if untreated, entails protracted bacterial bronchitis (at the mild end) to irreversible airway dilatation with cystic formation as determined by HRCT (at the severe end of the spectrum). Increasing evidence suggests that progression of airway damage can be limited by intensive treatment, even in those predestined to have bronchiectasis (eg immune deficiency). Treatment is aimed at achieving a cure in those at the milder end of the spectrum to limiting further deterioration in those with severe ‘irreversible’ radiological bronchiectasis.